Add a script to Generate the Docker official-images file
diff --git a/update-official-library.sh b/update-official-library.sh
new file mode 100755
index 0000000..07e3b1f
--- /dev/null
+++ b/update-official-library.sh
@@ -0,0 +1,36 @@
+#!/bin/bash -eu
+
+# Generate the Docker official-images file
+
+sha() {
+ local branch=$1
+ git rev-parse $branch
+}
+
+version_from_dockerfile() {
+ local branch=$1
+ git show $branch:Dockerfile | grep JENKINS_VERSION: | sed -e 's/.*:-\(.*\)}/\1/'
+}
+
+master_sha=$(sha master)
+alpine_sha=$(sha alpine)
+
+master_version=$(version_from_dockerfile master)
+alpine_version=$(version_from_dockerfile alpine)
+
+if ! [ "$master_version" == "$alpine_version" ]; then
+ echo "Master version '$master_version' does not match alpine version '$alpine_version'"
+ exit 1
+fi
+
+cat << EOF > ../official-images/library/jenkins
+# maintainer: Nicolas De Loof <nicolas.deloof@gmail.com> (@ndeloof)
+# maintainer: Michael Neale <mneale@cloudbees.com> (@michaelneale)
+# maintainer: Carlos Sanchez <csanchez@cloudbees.com> (@carlossg)
+
+latest: git://github.com/jenkinsci/jenkins-ci.org-docker@$master_sha
+$master_version: git://github.com/jenkinsci/jenkins-ci.org-docker@$master_sha
+
+alpine: git://github.com/jenkinsci/jenkins-ci.org-docker@$alpine_sha
+$alpine_version-alpine: git://github.com/jenkinsci/jenkins-ci.org-docker@$alpine_sha
+EOF